Tooth hydroxyapatite (HAP)

Tooth hydroxyapatite is the principal inorganic mineral component of human dental enamel and dentin, comprising 70–95% of their mass. It is a crystalline calcium phosphate compound with the chemical formula Ca₁₀(PO₄)₆(OH)₂. Hydroxyapatite provides the hardness and structural resiliency of teeth, forming densely packed rods (and interrods) surrounded by a small organic matrix and water[2][4][5]. Enamel hydroxyapatite is highly resistant to mechanical wear but vulnerable to acidic dissolution (demineralization) during caries and erosion. Remineralization therapies—including toothpastes and dental treatments—sometimes employ biomimetic or synthetic hydroxyapatite to replace lost mineral content, leveraging its chemical similarity and high biocompatibility. Hydroxyapatite is a mineral and not a protein, receptor, or enzyme, and therefore is not considered a therapeutic target in the pharmacological sense; it is instead a substrate for biomaterials or restorative interventions, not a direct drug target[1][3][5].

Other names

HydroxyapatiteHydroxylapatiteCa₁₀(PO₄)₆(OH)₂Tooth mineralDental apatiteEnamel apatite

Null (not a direct drug target; mechanistically, exogenous HAP can promote remineralization by direct mineral deposition and occlusion of enamel micropores[1][3][5].)